Octopuses use human waste for shelter, camouflage and more, study finds

A new study suggests it’s increasingly common for octopuses to use bottles, cans and other human waste for shelter, camouflage their dens and even house their young.

“We think it’s because of the great abundance of these man-made objects – you know, garbage – in the ocean,” said lead author Maira Proietti, an oceanographer at the Federal University of Rio Grande in Brazil. . As it happens guest host Gillian Findlay.

“It’s becoming so common that they use these items for protection instead of their natural shelters, like seashells, which are becoming scarce in the ocean.”

The results are not surprising. Marine scientists and others who work on the ocean have long observed octopuses taking up residence in sunken bottles and containers. In fact, those who study creatures often use such objects to attract and capture them.

But the new study, published in last month’s Marine Pollution Bulletinis the first to use participatory photography to examine how widespread the behavior is.

Hundreds of crowdsourced photographs

The researchers examined 261 photographs of 24 different species of octopus interacting with ocean litter from around the world.

“Through these images, we have observed that it is very common for these benthic species [deep-sea] octopuses to use artificial shelters instead of natural ones,” Proietti said.

Glass objects were present in 41.6% of the photos, while plastic was observed in 24.7%.

Earlier this month, the UN approved a historic agreement to create the first-ever global treaty on plastic pollution calling plastic in the world’s oceans an “epidemic”.

Some photos showed octopuses using the trash as makeshift shelters, or even using pieces of trash to camouflage their natural dens. Others showed females using litter to house their eggs.

Still others showed the creatures “walking on stilts” – using their tentacles to walk along the seabed – while clinging to various objects they had collected.

An octopus takes refuge in a broken glass bottle. (Jean-Paul Meillon)

“At first glance, this would seem like a positive thing because since they don’t have natural shelters, they at least have artificial ones to avoid predation and protect themselves,” Proietti said. “But it could also be concerning.”

At least one octopus has been pictured sheltering in a broken glass bottle, she said, which could lead to injury. In another case, an octopus was sheltering in an old car battery, which it says could emit chemicals dangerous to marine life.

Methodological concerns

Stefan Linquist, philosopher and naturalist from the University of Guelph who studied the social behavior of octopusessays the results are not surprising and present an interesting case study for the use of participatory photography in marine studies.

While studying octopuses in New South Wales, he says he observed octopuses using discarded scallops to build shelters. These creatures also appeared to have gathered around a large concrete block on the ocean floor to provide additional shelter.

An octopus finds refuge in a plastic bottle. (Claudio Sampeio)

That said, Linquist says he has concerns about the study’s methodology. On the one hand, he says he’s missing a control subject — another animal to compare octopuses to.

“Ideally, you’d want a comparable species that also digs burrows for shelter. Then we could at least ask the question of whether octopuses are more or less dependent on litter, based on the images. In the state current affairs, we have no comparative information,” he said in an email.

Proietti says they weren’t able to study a second species because crowdsourcing the octopus photos alone was already an “extremely laborious” process, but that it would be a good idea for follow-up research.

Additionally, Linquist says what appears to be an increase in the number of junk-using creatures may actually just be increasing the availability of photographic evidence. Underwater photography has become more popular and accessible in recent years, he said.

Proietti admits that’s a possibility, and the study includes that caveat as well.

Despite these limitations, Proietti says what they observed was disturbing.

“Unfortunately, we are living in a huge environmental crisis…not only climate change, but also this litter pollution in the ocean is extremely worrying,” Proietti said.

“We need to stop the sources and collect what’s in the ocean ASAP because the impacts will only increase as well.”

Written by Sheena Goodyear. Interview with Maira Proietti directed by Katie Geleff.

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